Watch List notes:

Gallienus (253-268). Joint reign. AR Antoninianus, 256-258. Obv. Head right, radiate. Rev. Mars standing right in military attire; holding spear and trophy. RIC V cf. 185 and 186. AR. 2.61 g. 24.50 mm. VF. On this dramatic and interesting double-struck coin, the flan moves and rotates c. 90° between the two strikes.